Does incline walking affect the knees?

Impact of Incline Walking on Knee Health

Incline walking can be beneficial for knee health as it decreases the internal knee abduction moment, potentially reducing medial compartment loading and lowering the risk of knee osteoarthritis development or progression. 1, 2

Effects of Incline Walking on Knee Biomechanics

Positive Effects

• Incline walking significantly decreases peak internal knee-abduction moment compared to level walking 1
• This reduction occurs in a dose-dependent manner with increasing incline gradients (in 10% increments) 2
• Lower knee abduction moments may reduce:
  • Medial compartment loading
  • Cartilage degeneration
  • Risk of developing or worsening knee osteoarthritis

Considerations for Different Populations

• Particularly beneficial for:
  • Older adults seeking exercise without exacerbating knee joint stress 2
  • Individuals post-knee surgery
  • Obese individuals who need low-impact exercise options
  • Those with early or established knee osteoarthritis

Recommendations for Safe Implementation

Gradient Considerations

• Start with moderate inclines (10-15%) which show significant reductions in knee abduction moments 1, 2
• Progress gradually to higher inclines (up to 20%) as tolerated
• Avoid excessive downhill walking, which may increase peak tibial acceleration 3

Duration and Intensity

• For individuals with severe knee osteoarthritis, up to 70 minutes per week of moderate-intensity supervised walking appears safe and feasible 4
• Higher doses (95 minutes) may increase risk of exacerbating knee pain 4
• Use the "small amounts often" principle for exercise pacing 3

Biomechanical Factors and Precautions

Biomechanical Considerations

• Knee joint angle and muscle pre-activation have greater effects on tibial acceleration than surface compliance alone 3
• Proper form is essential to maximize benefits and minimize risks
• Consider addressing any existing biomechanical abnormalities through:
  • Quadriceps strengthening 3
  • Range-of-motion/flexibility exercises 3
  • Proper footwear 3

Potential Risks

• A single 30-minute walk may temporarily increase pressure pain sensitivity at the affected knee in individuals with knee osteoarthritis 5
• Inflammatory and immune protein pathways may be activated during walking in those with knee osteoarthritis 5
• Excessive walking duration may exacerbate symptoms in those with severe knee osteoarthritis 4

Alternative Considerations

Other Low-Impact Options

• Elliptical training can be a safe alternative, particularly in reverse direction at lower inclines for those with knee pathologies 6
• Low-impact aerobic fitness exercises are recommended for symptomatic knee osteoarthritis 3
• Quadriceps strengthening exercises are suggested for symptomatic knee osteoarthritis 3

Conclusion

Incline walking represents a promising exercise modality that can provide cardiovascular benefits while potentially reducing harmful knee joint loading. The biomechanical advantages of decreased knee abduction moments during incline walking make it particularly suitable for individuals concerned about knee joint health or those with existing knee conditions.